Method for treating hatching eggs and method for hatching eggs

ABSTRACT

A method for treating a fertilized egg of a bird, a method for increasing the body weight of a chick at hatch, and a method for increasing the hatchability of a fertilized egg of a bird, comprising injecting, into the fertilized egg after start of incubation, a solution containing amino acids which determine the nutritive value of proteins in the fertilized egg; a method for hatching a fertilized egg of a bird, comprising hatching the fertilized egg after start of incubation treated according to the treatment method; a fertilized egg of a bird after start of incubation, the egg being treated according to the treatment method; and a bird hatched from the fertilized egg.

TECHNICAL FIELD

The present invention relates to an improvement of a method forproducing chicks by artificial hatch of fertilized eggs of birds. Moreparticularly, the present invention relates to a method for enhancingthe productivity of chicks by carrying out a treatment for supplyingnutrition by injecting a mixed solution of amino acids into fertilizedeggs.

BACKGROUND OF THE INVENTION

In the factories of producing chicks including broilers, efforts forimprovement have been made for enhancing the productivity of hatchedchicks until they grow to a stage suitable for eating. For example, inchickens, it is tried to accelerate the growth by adding variousnutrition-supplements such as vitamins to feeds.

Moreover, since the size of chicks hatched from fertilized eggs and thegrowth rate after hatch are generally proportional to the size andprotein amount of fertilized eggs, much efforts for improving nutritionof parent chickens have been made for the purpose of producingfertilized eggs having a large size and containing a large amount ofproteins. However, an egg-production ratio is generally low in theparent chickens laying fertilized eggs having a large size andcontaining a large amount of proteins. Therefore, the feeding cost forthe parent chickens cannot be disregarded, which is required forsecuring regularly a large number of such fertilized eggs having a largesize and containing a large amount of proteins.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a method capable ofsupplying regularly a large number of chicks at a low cost, the chickshaving body weight at hatch heavier than that usually expectable fromthe size of fertilized eggs and being capable of shortening the termnecessary for reaching a stage suitable for eating after hatch. Morespecifically, an object of the present invention is to provide a methodfor treating fertilized eggs for obtaining fertilized eggs capable ofsupplying chicks which have heavy body weight at hatch and are capableof shortening the term necessary for reaching a stage suitable foreating after hatch.

In order to achieve the above and other objects, the present inventionbasically relates to injection of amino acids into fertilized eggs ofbirds, the amino acids being substances determining the nutritive valueof the proteins in the fertilized eggs, and the present inventionincludes the following each invention.

-   (1) A method for treating a fertilized egg of a bird, comprising    injecting, into the fertilized egg after start of incubation, a    solution containing amino acids which determine the nutritive value    of proteins in the fertilized egg.-   (2) The method according to (1), wherein the fertilized egg is a    chicken egg on days 13 to 19 of the incubation.-   (3) The method according to (1), wherein the fertilized egg is a    chicken egg on days 13 to 14 of the incubation.-   (4) The method according to any one of (1) to (3), k wherein the    solution containing amino acids is a mixed solution of amino acids    having a composition which is almost the same as the amino acid    composition in the fertilized egg before the start of incubation.-   (5) The method according to any one of (1) to (4), wherein the    solution containing amino acids contains an antioxidant, a    nutritional supplement other than said amino acids, and/or a    vaccine.-   (6) A method for hatching a fertilized egg of a bird, comprising    hatching the fertilized egg after start of incubation treated    according to the method of any one of (1) to (5).-   (7) A method for increasing the body weight of a chick at hatch,    comprising injecting, into a fertilized egg after start of    incubation, a solution containing amino acids which determine the    nutritive value of proteins in the fertilized egg.-   (8) The method according to (7), wherein the fertilized egg is a    chicken egg on days 13 to 19 of the incubation.-   (9) The method according to (7), wherein the fertilized egg is a    chicken egg on days 13 to 14 of the incubation.-   (10) The method according to any one of (7) to (9), wherein the    solution containing amino acids is a mixed solution of amino acids    having a composition which is almost the same as the amino acid    composition in the fertilized egg before the start of incubation.-   (11) The method according to any one of (7) to (10), wherein the    solution containing amino acids contains an antioxidant, a    nutritional supplement other than said amino acids, and/or a    vaccine.-   (12) A method for increasing the hatchability of a fertilized egg of    a bird, comprising injecting, into the fertilized egg after start of    incubation, a solution containing amino acids which determine the    nutritive value of proteins in the fertilized egg.-   (13) The method according to (12), wherein the fertilized egg is a    chicken egg on days 13 to 19 of the incubation.-   (14) The method according to (12), wherein the fertilized egg is a    chicken egg on days 13 to 14 of the incubation.-   (15) The method according to any one of (12) to (14), wherein the    solution containing amino acids is a mixed solution of amino acids    having a composition which is almost the same as the amino acid    composition in the fertilized eggs before the start of incubation.-   (16) The method according to any one of (12) to (15), wherein the    solution containing amino acids contains an antioxidant, a    nutritional supplement other than said amino acids, and/or a    vaccine.-   (17) A fertilized egg of a bird after start of incubation, said egg    being treated according to the method of any one of (1) to (5).-   (18) A bird hatched from a fertilized egg after start of incubation,    said egg being treated in accordance with the method according to    any one of (1) to (5).

BEST MODE FOR CARRYING OUT THE INVENTION

The fertilized eggs to be treated by the method of the present inventionare not particularly limited, so long as the eggs are eggs of birdscapable of subjecting to artificial hatch. The injection of nutrientinto fertilized eggs by the above treatment of injecting amino acidsimproves not only the growth of embryos in the fertilized eggs after thestart of incubation but also the growth of chicks hatched from thetreated fertilized eggs. Therefore, the treating method of the presentinvention is particularly suitable for the treatment of fertilized eggsof chickens including broilers.

The composition of the solution containing amino acids for use in themethod of the present invention is not particularly limited as far asthe solution contains amino acids determining the proteins in fertilizedeggs. Preferred is a mixed solution of amino acids having a compositionwhich is almost the same as the amino acid composition in the fertilizedeggs before the start of acids for use in the method of the presentinvention is abbreviated as an “amino acid solution”.

Examples of a suitable amino acid solution include an amino acidsolution having a composition shown in Table 1.

In the amino acid composition in Table 1, it is possible to usephenylalanine instead of tyrosine. Moreover, any mixed solution of aminoacids having the composition ratio of amino acids shown in Table 1 canbe employed even when the concentration is different.

TABLE 1 (Composition of Amino Acids) Amino acid (g/l) Asparagine 10.6 ±1  Threonine 5.0 ± 1 Serine 7.7 ± 1 Glutamine 14.0 ± 1  Glycine 3.5 ± 1Alanine 6.0 ± 1 Valine 6.7 ± 1 Cystine 2.2 ± 1 Methionine 3.8 ± 1Isoleucine 5.4 ± 1 Leucine 9.1 ± 1 Tyrosine 1.7 ± 1 Phenylalanine 5.6 ±1 Lysine 7.6 ± 1 Histidine 2.7 ± 1 Arginine 6.5 ± 1 Proline 3.9 ± 1Tryptophan 1.9 ± 1

In the present invention, the amino acids are injected as a solution ina liquid, and the liquid to be used is not particularly limited unlessit adversely affects the incubation. Examples include distilled waterand physiological saline.

The concentration of the amino acid solution for use in the method ofthe present invention and the amount of amino acids to be injected arenot particularly limited, so long as necessary amounts of amino acidscan be administered into fertilized eggs. The amino acid solution can beused in a concentration range of usually 30 to 220 g/l, preferably 30 to180 g/l, and more preferably 50 to 160 g/l.

Moreover, the amount of the amino acid solution to be injected intofertilized eggs is an amount capable of administering a necessary amountof aimed amino acids into the fertilized eggs, and the amount to beinjected generally ranges from 0.2 to 1.0 ml/fertilized egg.

Furthermore, the amino acid solution may contain an antioxidant, anutritional supplement such as a vitamin, and other additives andcarriers which do not affect adversely on the hatch of fertilized eggsand the growth of birds.

The treatment of injecting the amino acid solution into fertilized eggsby the method of the present invention is subjected to the fertilizedeggs after the start of incubation. The part of injecting the amino acidsolution into the fertilized eggs after the start of incubation is theparts of egg yolk and albumen, and/or inner tissues of fertilized eggs,excluding an air cell and an embryo in the fertilized eggs. At the partof the air cell, the amino acid solution is blocked by chorioallantoisand thus no nutrition-supplying effect on the embryo is realized, whilethere is a possibility that the embryo is destroyed by entering theneedle for injection to cause no occurrence of hatch in injection intothe embryo part. Therefore, it is preferable to avoid the injection intothese parts.

The timing for injection is preferably the time when the embryo rapidlygrow in the fertilized eggs.

In chicken eggs, for example, with the growth of the embryo in afertilized egg, the egg yolk in saccus vitellinus gradually decreasesuntil about days 7 of the incubation, but rapid decrease of the egg yolkis observed on day 7 to about day 14, and then after day 14, thedecrease of the yolk becomes again gradual. From these facts, as thetiming for nutrition enhancement of incubating eggs by injecting aminoacids, the injection is effective on days 7 to 14 of the incubation.Particularly, the injection of amino acids is carried out on days 10 to14, more preferably on days 13 to 14, and particular preferably on day14 of the incubation. After day 14, the effect of injection is not soremarkable as compared with the injection until day 14, but the effectsof improving hatchability of fertilized eggs and body weight at thehatch by the injection of the amino acid solution can be expected untilday 19 depending on the kind of fertilized eggs.

Moreover, especially on days 10 to 14 of the incubation, the embryo isresistant to the amino acid solution even when the amino acid solutioncomes into contact with the growing embryo and the embryo is lessdamaged owing to low possibility of the contact with the needle, so thatthe part to be injected is not particularly limited. Accordingly, theinjection is preferably carried out during this term also from theviewpoint of the easiness of injection operation. When amino acids areinjected on days 7 to 9 of the incubation, the injection into the eggyolk part is preferable.

In fertilized chicken eggs, the parts of the egg yolk and albumen in thefertilized eggs have regions capable of easily inserting a needle forinjection into the parts until about day 14 after the start ofincubation and the embryo itself is resistant so as not to be damagedeasily by the needle for injection, so that the injection of the aminoacid solution is preferably carried out on day 14. As above, theinjection of the amino acid solution at the time when the embryo isresistant to the damage by the needle for injection, the growth of theembryo is rapid and nutrition consumption is fast provides an importanttechnical significance that the treatment of injecting amino acids canbe realized by means of an automatic apparatus which injects the aminoacid solution into a large number of fertilized eggs at once with alarge number of needles for injection arranged in a line. However, solong as a careful injection of amino acids is carried out so as not todamage the tissues in the fertilized eggs, the effects of the amino acidinjection can be fully expected even after day 14. In addition, theamino acid solution can be injected together with a vaccine such as thevaccine for Marek's disease.

The treatment of injecting amino acids according to the presentinvention can increase the body weight of chicks, for example, at hatchby 1 to 2% as the ratio of body weight at hatch/egg weight. Moreover,the hatchability can be increased, for example, by 5 to 30%.

EXAMPLES

The present invention is more specifically explained with reference toExamples, but the present invention is not limited to these Examples.

Example 1

Fertilized eggs of a broiler (Chunky) were sterilized with 70% alcoholand the eggs were divided into 6 groups, each group being composed of 10eggs, based on the measurement of egg weight so that each group had thesame average egg weight±standard deviation (51.2±0.2 g), followed byincubation at a temperature of 37.8° C. and a relative humidity of 60%.The eggs under incubation were checked every one week to removeundeveloped eggs. On day 14 of the incubation, one group was leftuntreated as a control group, and a hole was made at the eggshell on theair cell of each egg of remaining five groups, followed by injection of0.5 ml of a solution (hereinafter, referred to as “amino acid solution”)of an amino acid mixture dissolved in sterile distilled water into theegg yolk, the mixture being used in an amount so as to become aconcentration of 0, 53, 106, 159, or 212 mg/ml. Thereafter, the hole wasclosed with paraffin and the incubation was continued. The injectiontreatment was carried out aseptically in a clean bench.

The amino acid solution used for the injection had a composition similarto the composition shown in Table 1, with the exception that sparinglysoluble tyrosine was replaced by phenylalanine.

With regard to the fertilized eggs, the hatching time and the bodyweight at hatch were measured every one hour from day 19 of theincubation, the starting day of the incubation being zero day.

A 1 ml disposable syringe (manufactured by Terumo Corporation) was usedas the syringe for injecting the amino acid solution into the fertilizedeggs and 27G×¾″ (manufactured by Terumo Corporation) was used as theneedle for injection.

With regard to the hatchability, a significant difference was determinedby a χ-square test based on the results obtained. With regard to otherindexes, analysis of variance was carried out and difference betweenaverage values was tested by LSD method. The statistical risk was set to5%.

The results are shown in Table 2.

TABLE 2 Hatch- Body weight Body weight at Egg weight ability at hatchhatch/egg weight Treated group (g) (%) (g) (%) Control Group 51.0 ±2.9¹⁾ 70.0¹⁾ 36.9 ± 3.2¹⁾ 73.0 ± 2.6¹⁾ Amino acidin- jected Groups(mg/ml)  53.0 51.1 ± 2.0 90.0 36.5 ± 4.5 71.8 ± 7.6 106.0 51.5 ± 2.290.0 38.6 ± 1.9 75.0 ± 1.3 159.0 51.4 ± 2.4 80.0 38.0 ± 2.5 73.5 ± 2.1¹⁾Each value is an average value ± standard deviation of 10 fertilizedeggs.

Table 2 shows that the hatchability of the fertilized eggs of controlgroup is 70.0%, but the hatchability of the fertilized eggs to which theamino acid solution having a concentration of 53.0 mg/ml to 159.0 mg/mlwas injected is from 80 to 90%. This result apparently indicates thatthe method of the present invention contributes the enhancement ofhatchability of fertilized eggs.

Moreover, with regard to the body weight at hatch, the body weight athatch/egg weight of the fertilized eggs of the control group is73.0±2.6%, while the ratio of the fertilized eggs to which the aminoacid solution having a concentration of 53.0 mg/ml to 159.0 mg/ml wasinjected is the same as or higher than the value. In particular, thegroup injected with an amino acid solution having a concentration of106.0 mg/ml shows a value of 75.0±1.3%, which clearly indicates that theinjection of the amino acid solution is a method capable of obtainingchicks having heavier body weight at hatch than those of non-treatedfertilized eggs.

Example 2

Fertilized eggs of a broiler (Chunky) were sterilized with 70% alcoholand the eggs were divided into 6 groups, each group being composed of 10eggs, based on the measurement of egg weight so that each group has thesame average egg weight standard deviation (51.2±0.2 g), followed byincubation at a temperature of 37.8° C. and a relative humidity of 60%.The eggs under incubation were checked every one week to removeundeveloped eggs. Day 14 of the incubation, one group was left untreatedas a control group, and a hole was made at the eggshell on the air cellof each egg of remaining five groups, followed by injection of an aminoacid solution having a concentration of 106 mg/ml in an amount of fivedifferent levels, i.e., 0, 0.25, 0.5, 0.75, and 1 ml into the egg yolk.Thereafter, the hole was closed with paraffin and the incubation wascontinued. The injection treatment was carried out aseptically in aclean bench.

The amino acid solution used for the injection had a composition similarto the composition used in above Example 1, and the syringes and needlesfor injecting the amino acid solution into the fertilized eggs were alsothe same as those used in Example 1.

With regard to the fertilized eggs, the hatching time and the bodyweight at the hatch were measured every one hour from day 19 of theincubation, the starting day of the incubation being zero day.

With regard to the hatchability, a significant difference was determinedby a χ-square test based on the results obtained. With regard to otherindexes, analysis of variance was performed and difference betweenaverage values was tested by LSD method. The statistical risk was set to5%.

The results are shown in Table 3.

TABLE 3 Injected Hatch- Body weight Body weight at amino acid Egg weightability at hatch hatch/egg weight amount (ml) (g) (%) (g) (%) 0(Control) 58.3 ± 2.6¹⁾ 75.0¹⁾ 42.6 ± 2.6^(b1)) 73.7 ± 2.6^(b1)) 0.2558.3 ± 2.5 90.0 43.7 ± 2.3^(ab) 75.3 ± 2.7^(ab) 0.5 58.3 ± 2.5 85.0 43.8± 2.5^(ab) 75.4 ± 3.7^(ab) 0.75 58.3 ± 2.5 75.0 44.5 ± 2.3^(a) 76.4 ±3.3^(a) 1.0 58.3 ± 2.5 70.0 43.5 ± 2.5^(ab) 74.8 ± 3.3^(ab) 0.5 58.3 ±2.5 70.0 43.4 ± 2.2^(ab) 74.3 ± 1.8^(ab) (212 mg/ml) ¹⁾Each value is anaverage value ± standard deviation of 20 fertilized eggs. ^(ab)There isa significant difference between different symbols by LSD method (P <0.05).

Table 3 shows that the hatchability of the fertilized eggs of thecontrol group is 75.0%, but the hatchability of the fertilized eggs towhich 0.25 ml or 0.5 ml of the amino acid solution having aconcentration of 106.0 mg/ml was injected is from 85 to 90%. Moreover,with regard to the body weight at hatch/egg weight (%), the body weightat hatch/egg weight of the fertilized eggs of the control group is73.0±2.6%, while the ratios of the fertilized eggs in the two cases were75.3±2.7% and 75.4±3.7%, respectively, these values indicating asignificant difference from the control. Furthermore, when the injectedamount of the amino acid solution was 1.0 ml and when 0.5 ml of theamino acid solution having doubled concentration was injected so thatthe injected amount of amino acids is the same, the hatchability is thesame, i.e., 70.0% which is inferior to the value of the control group,but the body weight at hatch/egg weight (%) is 74.8±3.3% and 74.3±1.8%,while the value of the control group is 73.7±2.6%. Thus, the significantdifference can be confirmed.

Example 3

Influence of the injection of amino acid into broiler fertilized eggs atlater stage of incubation on hatchability and body weight at hatch:

Fertilized eggs of Cobb broiler were divided into seven groups, eachgroup being composed of 20 eggs.

In order to examine the influence of the injection of amino acids atlater stage of incubation on hatchability, seven groups were set, onegroup being a control and amino acids being injected into the eggs ofeach one of the remaining six groups at each one day of from day 14 ofthe incubation to day 19 which is immediately before hatch. Fertilizedeggs having an average egg weight of 68 g were used and incubated at atemperature of 37.8° C. and a relative humidity of 60%. Specifically,the following groups were set: a control group; and seven groups intotal wherein 0.5 ml of 106 mg/ml of an amino acid solution having theprotein composition which is the same as that of the whole egg proteinswas injected into each of the fertilized eggs on days 14, 15, 16, 17, 18and 19 of the incubation. A 1 ml syringe for tuberculinization and aneedle of 27G×¾′ were used for the injection of amino acids.

Hatchability and body weights at hatch were measured. The resultsobtained were subjected to a χ-square test to compare the hatchability.The other results were subjected to analysis of variance.

Since fertilized eggs exhibiting very high hatchability were used, thehatchability in the control group was found to be a high rate, i.e.,96.4%, and the injected group on day 14 of the incubation resulted in asimilar high hatchability (Table 4). However, the hatchability decreasedin the groups wherein the injection was carried out thereafter. Thereason why the hatchability decreased is considered that the amino acidsolution was injected into the air cell because the needles used for theinjection were short. Only one example of no hatch because of theinsertion of the needle into embryo was observed among the injectedgroup injected on day 19 of the incubation. From these results, there isa possibility of overcoming the problem of hatchability by investigatingthe conditions for injecting amino acids and the problem is notsignificant when the injection of the vaccine for Marek's disease isconsidered.

TABLE 4 Initial egg Hatched egg Hatch- Body weight Body weight TreatedEgg weight weight ability at hatch at hatch/egg day numbers (g) (g) (%)(g) weight (%) Control 29 65.6 ± 4.8 65.6 ± 5.0 96.6 49.1 ± 3.5 74.9 ±2.5^(b) 14 33 65.7 ± 4.8 65.8 ± 5.0 96.9 50.0 ± 3.5 76.1 ± 2.1^(ab) 1531 67.9 ± 4.8 65.9 ± 4.4 93.5 50.1 ± 3.3 76.2 ± 5.3^(ab) 16 31 66.6 ±4.8 65.9 ± 4.8 93.5 50.7 ± 3.2 77.1 ± 1.6^(ab) 17 28 65.7 ± 4.8 65.9 ±5.0 89.3 49.6 ± 3.3 75.4 ± 1.2^(ab) 18 32 65.7 ± 4.8 65.4 ± 4.5 87.549.2 ± 3.7 75.2 ± 3.0^(b) 19 32 65.7 ± 4.8 65.7 ± 5.0 90.6 49.6 ± 4.675.5 ± 4.5^(ab) ^(ab)There is a significant difference between differentsymbols. The values are shown by average ± standard deviation.Hatchability is calculated excluding unfertilized eggs.

Example 4

Influence of the injection of amino acid into fertilized eggs ofdifferent kind of broilers at later stage of incubation on hatchabilityand body weight at hatch:

Two hundred fertilized eggs of Cobb and Arbor Acres broilers werepurchased and the eggs were divided into 2 groups per each kind ofchickens, each group being composed of 50 eggs, so that each group hadthe same average egg weight (65.0±4.0 g and 64.9±4.2 g; average eggweight±standard deviation). One group was a control group. With regardto the fertilized eggs, the starting day of the incubation was zero day,and a group to which an amino acid solution was injected was set.

Incubation was carried out at a temperature of 37.8° C. and a relativehumidity of 60%. The eggs under incubation were checked every one weekto remove undeveloped eggs.

Day 19 of the incubation, all the fertilized eggs were taken out of theincubator, and a hole was made at the eggshell on the air cell of eachegg of the group to be injected with amino acids, followed by injectionof 0.5 ml of a solution (hereinafter, referred to as an “amino acidsolution”) of an amino acid mixture dissolved in sterile distilled waterinto the egg yolk, the mixture being used in an amount so as to become aconcentration of 106 mg/ml. Thereafter, the hole was closed withparaffin, the eggs were returned to the incubator with in 1 hour fromthe taken-out, and the incubation was continued. The injection treatmentwas carried out aseptically in a clean bench.

After hatching, the hatching time and the body weight at the hatch weremeasured.

The amino acid solution used for the injection had a composition similarto the composition shown in Table 1 with the exception that sparinglysoluble tyrosine was replaced by phenylalanine. A 1 ml disposablesyringe (manufactured by Terumo Corporation) was used as the syringe forinjecting the amino acid solution into the fertilized eggs and 27G×¾″(manufactured by Terumo Corporation) was used as the needle.

With regard to the hatchability, a significant difference was determinedby a χ-square test based on the results obtained. With regard to otherindexes, analysis of variance was performed. The statistical risk wasset to 5%.

As shown in Table 5, the hatchability of the fertilized eggs of ArborAcres broiler is 87.8% in the amino acid-injected group, which is almostthe same as 87.4% in the control group, so that no difference betweenthem was observed. Moreover, in the case of the fertilized eggs of Cobbbroiler, the hatchability is 86.7% in the amino acid-injected group,which is slightly higher than 84.4% in the control group.

The ratio of the body weight at hatch/egg weight is significantlyincreased by the injection of amino acids irrespective of the differenceof kind of chickens.

TABLE 5 Initial Hatched Body egg egg Hatch- weight of Body weight Eggweight weight ability chick at at hatch/egg Line Group numbers (g) (g)(%) hatch (g) weight (%) Arbor control 48 64.9 ± 4.8 65.0 ± 4.3 87.448.0 ± 3.4 74.0 ± 0.6 Acres injected 49 64.9 ± 4.8 64.8 ± 4.0 87.8 48.4± 3.8 74.7 ± 1.4 Cobb control 45 64.9 ± 4.8 64.7 ± 3.0 84.4 47.0 ± 3.072.6 ± 0.7 injected 45 65.0 ± 4.8 65.1 ± 4.3 86.7 48.1 ± 3.8 73.8 ± 1.5P< line NS NS NS 0.05 injected NS NS NS 0.05 inter- NS NS NS NS actionThe values are shown by average ± standard deviation. Hatchability iscalculated excluding unfertilized eggs. NS = no significant difference

INDUSTRIAL APPLICABILITY

According to the present invention, one or all of the purposes ofimproving hatchability of fertilized eggs and enhancing body weight athatch/egg weight (%) can be accomplished by appropriately selecting thecombination of the concentration and amount of an amino acid solution tobe used in the method of injecting amino acids into fertilized eggs at asuitable stage after the start of incubation.

1. A method for treating a fertilized egg of a bird, comprisinginjecting, into a fertilized egg after start of incubation, a solutioncomprising amino acids which determine the nutritive value of proteinsin said fertilized egg, wherein said solution comprising amino acidsfurther comprises at least one ingredient selected from the groupconsisting of an antioxidant, a nutritional supplement other than saidamino acids, a vaccine, and mixtures thereof.
 2. The method according toclaim 1, wherein said fertilized egg is a chicken egg on days 13 to 19of incubation.
 3. The method according to claim 1, wherein saidfertilized egg is a chicken egg on days 13 to 14 of incubation.
 4. Themethod according to any one of claims 1 to 3, wherein said solutioncomprising amino acids is a mixed solution of amino acids having acomposition which is almost the same as the amino acid composition insaid fertilized egg before the start of incubation.
 5. A method forhatching a fertilized egg of a bird, comprising hatching a fertilizedegg after start of incubation treated according to the method of any oneof claims 1 to
 3. 6. A fertilized egg of a bird after start ofincubation, said egg being treated according to the method of any one ofclaims 1 to
 3. 7. A bird hatched from a fertilized egg after start ofincubation, said egg being treated in accordance with the methodaccording to any one of claims 1 to
 3. 8. A method for increasing thebody weight of a chick at hatch, comprising injecting, into a fertilizedegg after start of incubation, a solution comprising amino acids whichdetermine the nutritive value of proteins in said fertilized egg,wherein said solution comprising amino acids further comprises at leastone ingredient selected from the group consisting of an antioxidant, anutritional supplement other than said amino acids, a vaccine, andmixtures thereof.
 9. The method according to claim 8, wherein saidfertilized egg is a chicken egg on days 13 to 19 of incubation.
 10. Themethod according to claim 8, wherein said fertilized egg is a chickenegg on days 13 to 14 of incubation.
 11. The method according to any oneof claims 8 to 10, wherein said solution comprising amino acids is amixed solution of amino acids having a composition which is almost thesame as the amino acid composition in said fertilized egg before thestart of incubation.
 12. A method for increasing the hatchability of afertilized egg of a bird, comprising injecting, into said fertilized eggafter start of incubation, a solution comprising amino acids whichdetermine the nutritive value of proteins in said fertilized egg,wherein said solution comprising amino acids further comprises at leastone ingredient selected from the group consisting of an antioxidant, anutritional supplement other than said amino acids, a vaccine, andmixtures thereof.
 13. The method according to claim 12, wherein saidfertilized egg is a chicken egg on days 13 to 19 of incubation.
 14. Themethod according to claim 12, wherein said fertilized egg is a chickenegg on days 13 to 14 of incubation.
 15. The method according to any oneof claims 12 to 14, wherein said solution comprising amino acids is amixed solution of amino acids having a composition which is almost thesame as the amino acid composition in said fertilized egg before thestart of incubation.
 16. A method of preparing a treated fertilized egg,said method comprising injecting, into a fertilized egg after start ofincubation, a solution comprising amino acids which determine thenutritive value of proteins in said fertilized egg, wherein saidsolution comprising amino acids further comprises at least oneingredient selected from the group consisting of an antioxidant, anutritional supplement other than said amino acids, a vaccine, andmixtures thereof.
 17. The method according to claim 16, wherein saidfertilized egg is a chicken egg on days 13 to 19 of incubation.
 18. Themethod according to claim 16, wherein said fertilized egg is a chickenegg on days 13 to 14 of incubation.
 19. The method according to any oneof claims 16 to 18, wherein said solution comprising amino acids is amixed solution of amino acids having a composition which is almost thesame as the amino acid composition in said fertilized egg before thestart of incubation.
 20. A method of preparing a bird chick, said methodcomprising hatching a treated fertilized egg, wherein said treatedfertilized egg is prepared by a method comprising injecting, into afertilized egg after start of incubation, a solution comprising aminoacids which determine the nutritive value of proteins in said fertilizedegg, wherein said solution comprising amino acids further comprises atleast one ingredient selected from the group consisting of anantioxidant, a nutritional supplement other than said amino acids, avaccine, and mixtures thereof.
 21. The method according to claim 20,wherein said fertilized egg is a chicken egg on days 13 to 19 ofincubation.
 22. The method according to claim 20, wherein saidfertilized egg is a chicken egg on days 13 to 14 of incubation.
 23. Themethod according to any one of claims 20 to 26, wherein said solutioncomprising amino acids is a mixed solution of amino acids having acomposition which is almost the same as the amino acid composition insaid fertilized egg before the start of incubation.